AIM To explore whether plasma vasoactive substances and neutrophil infiltration make different contribution in cerebral ischemia-reperfusion injury and protective effect of triacetylshikimic acid(TSA). METHODSThe rat models of ischemia 90 min and reperfusion 3-48 h were prepared with middle cerebral artery occlusion. TSA 50-200 mg·kg-1 were given (ig) immediately and 60 min again after the onset of ische- mia. Serotonin and thromboxane B2 (TXB2) concentrations in plasma were detected by fluorescence spectrophotometry and radioimmunoassay respectively. Myeloperoxidase(MPO) activity in brain tissue was quantified by chemical analysis. RESULTS At 3-24 h after reperfusion, the concentrations of plasmic serotonin, TXB2, and brain MPO activity increased obviously in a time-dependent manner. At 48 h after reperfusion, the concentrations of serotonin and TXB2 decreased to the same level of sham. Nevertheless, brain MPO activity remained more elevated than the contralateral cortex. At 24 h after reperfusion, TSA (100 and 200 mg·kg-1) was shown to possess the ability to inhibit the increased plasmic serotonin, TXB2 concentrations, and brain MPO activity induced by focal cerebral ischemia-reperfusion. CONCLUSION Vasoactive substances in plasma and MPO activity in brain tissue show different time courses during focal cerebral ischemia-reperfusion and make different contribution to brain damage. TSA is effective to protect the ischemic brain tissue from ischemia-reperfusion injury.

Objective: To measure the fracture strength of the posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps with highly temperature-resistant adhesive and to provide re-ference data for clinical application. Methods: A standard low dental cast was achieved with 46 missing. Five posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps, with abutments being 47 and 45 . The low dental cast was fixed on the panel of the universal testing machine, vertical load given on the central of the pontic as the velocity of 2 mm/min. Results: The fracture strength of the posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps was (877.00?126.53) N, the fracture strength of the metal frame was (1 448.94?51.02) N. Conclusion: Posterior galvano-ceramic bridges made by Ni-Cr pontic fired bonding galvano caps could endure the normal human occlusal force.

Objective:To investigate the difference of curative effect between zero-profile bridge-shaped locking cage (ROI-C) and anterior cage combined with titanium plate fixation in the treatment of two-level and three-level cervical spondylotic myelopathy.Methods:A total of 85 patients (43 males and 42 females), aged 52.3±8.0 years (range from 28 to 66 years) with bi- and three-level cervical spondylotic myelopathy who received surgical treatment from June 2017 to October 2019 were retrospectively analyzed. There were 63 cases of two levels and 22 cases of three levels. 45 cases were treated with zero-profile bridge-shaped locking cage ROI-C (ROI-C group), and 40 cases with anterior cage combined with titanium plate fixation (titanium plate group). The main observation indicators include operation time, intraoperative blood loss, cervical Cobb angle, fusion segment Cobb angle, average intervertebral height, pain visual analogue scale (VAS), Japanese Orthopaedic Association (JOA) Score and neck disability index (NDI).Results:All of 85 patients were followed up for 16.9±2.0 months (range 12 to 22 months). The operation time of two-level ROI-C group was 110.37±8.25 min, which was shorter than 139.5±10.54 min of titanium plate group; the intraoperative blood loss was 15.74±8.10 ml, which was less than 23.71±9.70 ml of titanium plate group; the operation time of three-level ROI-C group was 130.00±5.70 min, which was shorter than 162.83±5.59 min of titanium plate group, while the difference in the intraoperative blood loss between the two groups had no statistical significance. One year after operation, Cobb angle of cervical vertebra in double and three-level ROI-C groups were 15.31°±1.55° and 15.20°±0.42°, respectively, which were largerthan 11.23°±2.03° and 9.20°±1.14° before operation; in titanium plate group, they were 15.89°±1.13° and 16.08°±1.88°, which were higher than 11.25°±2.01° and 9.00°±1.60° before operation, and the differences had statistical significance. The differences between the two groups before operation and 1 year after operation had no statistical significance. One year after operation, the VAS scores of double and three-level ROI-C groups were 1.83±0.66 points and 2.60±0.52 points, respectively, which were less than the preoperative 7.49±0.51 points and 7.60±0.52 points; the titanium plate group was 1.79±0.50 points and 2.41±0.51 points, which were less than the preoperative 7.61±0.63 points and 7.42±0.52 points, and the differences had statistical significance. There was no significant difference between the two groups before operation and 1 year after operation. One year after operation, the JOA scores of double and three-level ROI-C groups were 15.00±0.84 points and 14.70±0.95 points, respectively, which were higher than the preoperative 7.20±0.87 points and 6.60±1.27 points; the scores of titanium plate group were 15.29±0.85 points and 14.83±0.58 points, which were higher than the preoperative 6.89±1.03 points and 6.92±0.67 points, and the differences had statistical significance. The differences between the two groups had no statistical significance. The postoperative JOA improvement rate was excellent. Postoperative dysphagia occurred in 1 case (2.22%, 1/45) in ROI-C group and 8 cases (20.00%, 8/40) in titanium plate group, and the difference in the incidence rate between two groups had statistical significance ( χ2=5.32, P=0.02). Conclusion:Both ROI-C and anterior cage combined with titanium plate fixation in the treatment of double and three-level cervical spondylotic myelopathy can achieve good short-term clinical efficacy, with shorter operation time and lower incidence rate of postoperative dysphagia using ROI-C.

OBJECTIVETo investigate the effect of adjuvant chemotherapy on the prognosis of stage II( colon cancer patients with high risk factors.

METHODSClinicopathological and follow-up data of stage II( colon cancer patients undergoing radical surgery from January 2001 to March 2012 at Gastrointestinal Cancer Center of Peking University Cancer Hospital were retrospectively analyzed. The effect of adjuvant chemotherapy (within postoperative 2 month, fluorine uracil as main drugs) on the prognosis of high-risk patients was analyzed. High risk factors were defined as having at least one of the following factors: (1) tumor stage T4; (2) poor differentiation; (3) with vascular cancer embolus; (4) number of harvested lymph node less than 12; (5) complicated with obstruction or perforation.

RESULTSA total of 497 patients with stage II( colon cancer were included in this study, of whom 258 cases(51.9%) had high risk factors, including stage T4 tumor in 80 cases(16.1%), poor differentiation in 80 cases (16.1%), cancer embolus in 37 cases (7.4%), lymph node harvested number less than 12 in 88 cases (17.7%), and obstruction or perforation in 85 cases (17.1%). Among 497 patients, number of cases with 1 to 4 high risk factors was 170 (34.2%), 68 (13.7%), 16 (3.2%) and 4 (0.8%), respectively. The last follow-up time was December 2016. The 5-year overall survival rate of all the 497 patients was 81.7%. The 5-year overall survival rate of 239 patients without high risk factors was 87.0%. The 5-year survival rate in patients with 1 to 4 risk factors was 81.9%, 73.7%, 66.7% and 25.0%, respectively (P=0.001). There was no significant difference in 5-year survival rate between 103 patients with adjuvant chemotherapy and 394 patients without adjuvant chemotherapy (79.6% vs. 82.8%, P=0.814). In patients with high risk factors, 80(31.0%) received adjuvant chemotherapy. There was no significant difference of 5-year survival rate between 80 patients with adjuvant chemotherapy and 178 patients without adjuvant chemotherapy (81.4% vs. 74.7%, P=0.147). Multivariate analysis showed that preoperative CEA level, T4 stage, lymph node harvested number, and tumor differentiation were the independent prognostic factors of patients with stage II( colon cancer (all P<0.05).

CONCLUSIONSThe proportion of patients with at least one risk factor is quite high in stage II( colon cancer cases. Adjuvant chemotherapy can not prolong the overall survival time of high risk patients.

The effect of the endophytic fungi Botrytis sp. (C1) or Chaetomium globosum (C4) on the drought resistance of Chrysanthemum morifolium was studied. Ch. morifolium plantlets were inoculated with C1, C4 and cultured in the pots for 60 days, then the plantlets were stressed by 0%, 10%, 20%, 30%, 40% PEG6000 respectively in order to simulate different drought conditions. Biomass, the activities of SOD, POD, PAL, the contents of MDA and soluble protein of each group were determined. The results showed that endophytic fungi groups grew better than the control (without inoculation endophytic fungi). With the increasing of the concentration of PEG6000, the biomass of Ch. morifolium of each groups decreased, while the biomass of fungi groups was significantly higher than that of control, moreover C4 group higher than C1 group. With the concentration of PEG increasing, the content of MDA of each group increased too, while POD activity and soluble protein content of all treatments increased at first and then decreased. SOD activity and PAL activity of the control were increased with the increase of PEG concentration, but SOD activity of the two fungi groups were stable. After been stressed by different concentrations of PEG, MDA content of two fungi groups were always lower than the control, while SOD activity, POD activity, PAL activity and soluble protein content were higher. In conclusion, endophytic fungi can increase the drought resistance of Ch. morifolium.
Biomass ; Botrytis ; drug effects ; growth & development ; isolation & purification ; Chaetomium ; drug effects ; growth & development ; isolation & purification ; Chrysanthemum ; drug effects ; metabolism ; microbiology ; Droughts ; Peroxidases ; metabolism ; Polyethylene Glycols ; pharmacology ; Stress, Physiological ; drug effects ; Superoxide Dismutase ; metabolism

Clinical medicine is a practical, highly skilled natural science. Solid clinical skills are the cornerstone of medical students' growth and development. According to the change of medical education environment, the tension of doctor-patient relationship and the lack of practical ability, we build a set allround , systematic clinical practice teaching system based on practice curriculum teaching , centralized practice teaching, social practice teaching, practice skills assessment and practice skills competition. The research and practice of the system not only promotes teachers' and student's emphasis on the training of clinical practical skills but also improves student's clinical practice skills, strengthen teachers' clinical skills teaching ability, and boost the construction of clinical skills experimental center.

Objective: To understand the perceptions, attitudes and treatment selection of Chinese surgeons on the "watch and wait" strategy for rectal cancer patients after achieving a clinical complete response (cCR) following neoadjuvant chemoradiotherapy (nCRT). Methods: A cross-sectional survey was used in this study. Selection of subjects: (1) Domestic public grade III A (provincial and prefecture-level) oncology hospitals or general hospitals possessing the radiotherapy department and the diagnosis and treatment qualifications for colorectal cancer. (2) Surgeons of deputy chief physician or above. Using the "Questionnaire Star" online survey platform to create a questionnaire about cognition, attitude and treatment choice of the "watch and wait" strategy after cCR following nCRT for rectal cancer. The questionnaire contained 32 questions, such as the basic information of doctor, the current status of rectal cancer surgery, the management of pathological complete remission (ypCR) after nCRT for rectal cancer, the selection of examination items for diagnosis of cCR, the selection of suitable people undergoing "watch and wait" approach, the nCRT mode for promotion of cCR, the choice of evaluation time point, the willingness to perform "watch and wait" approach and the treatment choice, and the risk and monitoring of "watch and wait" approach. A total of 116 questionnaires were sent to the respondents via WeChat between January 31 and February 19, 2019. Statistical analysis was performed using Fisher′s exact test for categorical variables. Results: Forty-eight hospitals including 116 surgeons meeting criteria were enrolled, of whom 77 surgeons filled the questionnaire with a response rate of 66.4%. "Watch and wait" strategy was carried out in 76.6% (59/77) of surgeons. Seventy surgeons (90.9%) were aware of the ypCR rate of rectal cancer after preoperative nCRT and 49 surgeons (63.6%) knew the 3-year disease-free survival of patients with ypCR in their own hospitals. Fifty-five surgeons (71.4%) believed that patients with ypCR undergoing radical surgery met the treatment criteria and were not over-treated. Three most necessary examinations in diagnosing cCR were colonoscopy (96.1%, 74/77), digital rectal examination (DRE) (90.9%,70/77) and DWI-MRI (83.1%, 64/77). Responders preferred to consider a "watch and wait" strategy for patients with baseline characteristics as mrN0 (77.9%, 60/77), mrT2 (68.8%, 53/77) and well-differentiated adenocarcinoma (68.8%, 53/77). Sixty-six surgeons (85.7%) believed that long-term chemoradiotherapy (LCRT) with combination or without combination of induction and/or consolidation of the CapeOX regimen (capecitabine + oxaliplatin) should be the first choice as a neoadjuvant therapy to achieve cCR. Forty-one surgeons (53.2%) believed that a reasonable interval of judging cCR after nCRT should be ≥ 8 weeks. Forty-four surgeons (57.1%) routinely, or in most cases, informed patient the possibility of cCR and proposed to "watch and wait" strategy in the initial diagnosis of patients with non-metastatic rectal cancer. Thirteen surgeons (16.9%) would take the "watch and wait" strategy as the first choice after the patient having cCR. Fifty-two surgeons (67.5%) would be affected by the surgical method, that was to say, "watch and wait" approach would only be recommended to those patients who would achieve cCR and could not preserve the anus or underwent difficult anus-preservation surgery. Sixteen surgeons (20.8%) demonstrated that "watch and wait" strategy would not be recommended to patients with cCR regardless of whether the surgical procedure involved anal sphincter. Eleven surgeons (14.3%) believed that the main risk of "watch and wait" approach came from distant metastasis rather than local recurrence or regrowth. Twenty-nine of surgeons (37.7%) did not understand the difference between "local recurrence" and "local regrowth" during the period of "watch and wait". Twenty-six surgeons (33.8%) thought that the monitoring interval for the first 3 years of "watch and wait" strategy was 3 months, and the follow-up monitoring interval could be 6 months to 5 years. Surgeons from cancer specialist hospitals had higher approval rate, notification rate, and referral rate of "watch and wait" strategy than those from general hospitals. Thirty-one surgeons (42.5%) considered that the difficulty and concern of carrying out "watch and wait" approach in the future was the disease progress leading to medical disputes. Twenty-six surgeons (35.6%) demonstrated that their concern was lack of uniform evaluation standard for cCR. Conclusions Chinese surgeons seem to have inadequate knowledge of non-operative management for rectal cancer patients achieving cCR after nCRT and show relatively conservative attitudes toward the strategy. Chinese consensus needs to be formed to guide the non-operative management in selected patients. Chinese Watch & Wait Database (CWWD) is also needed to establish and provide more evidence for the use of alternative procedure after a cCR following nCRT.

Objective: To investigate the clinical effect of percutaneous curved vertebroplasty in the treatment of thoracolum-bar osteoporotic vertebral compression fractures (OVCFs). Methods: All of 85 patients with single thoracolumbar vertebral OVCFs who met the admission criteria from January 2017 to July 2018 were divided into three groups according to the random dig-its table method. They were treated with percutaneous curved vertebroplasty, routine unipedicular PVP and routine bipedicular PVP respectively. There were 25 patients in the percutaneous curved vertebroplasty group, 6 males and 19 females; aged 56-80 years, with an average age of 70.6±9.7 years. Fracture vertebral body distribution: T₁₀ 2 cases, T₁₁ 4 cases, T₁₂ 3 cases, L₁ 9 cases, L₂ 3 cases, L₃ 1 case, L₄ 1 case and L₅ 2 cases. There were 32 patients in the routine unipedicular PVP group, 6 males and 26 fe-males; aged 58-75 years, with an average age of 69.5±9.3 years. Fracture vertebral body distribution: T₁₀ 2 cases, T₁₁ 4 cases, T₁₂ 5 cases, L₁ 11 cases, L₂ 6 cases, L₃ 1 case, L₄ 1 case and L₅ 2 cases. There were 28 patients in the routine bipedicular PVP group, 5 males and 23 females; aged 59-81 years, with an average age of 69.8±8.8 years. Fracture vertebral body distribution: T₁₀ 2 cases, T₁₁ 4 cases, T₁₂ 4 cases, L₁ 10 cases, L₂ 4 cases, L₃ 1 case, L₄ 1 case and L₅ 2 cases. The operation time, injected cement volume, in-traoperative blood loss were recorded and analyzed. Preoperative, postoperative 1 week and 3 months visual analogue scale scores and oswestry disability index were adopted to value the clinical improvements. Preoperative, postoperative 1 week and 3 months relative vertebral height and kyphosis correction, and the cement leakage rate were measured and analyzed. Results: There was no significant difference in the data of gender, age, VAS scores, ODI and distribution of fracture vertebrae among the three groups (P>0.05), and the baseline data was comparable. The average VAS score in the percutaneous curved vertebroplasty group was 2.3±0.5 at 1 week after surgery, that of the routine unipedicular PVP group was 2.4±0.4 and that of the routine bipe-dicular PVP group was 2.4±0.4; the average ODI in the percutaneous curved vertebroplasty group was 19.8%±3.9%, that of the routine unipedicular PVP group was 20.0%±4.1% and that of the routine bipedicular PVP group was 19.9%±3.8%; they were lower than the preoperative data, which were statistically significant (P<0.001). The average relative vertebral height in the percutaneous curved vertebroplasty group was 48.99%±9.23% at 3 months after surgery, that of the routine unipedicular PVP group was 47.11%±10.12% and that of the routine bipedicular PVP group was 46.71%±11.16%; the average kyphosis cor-rection in the percutaneous curved vertebroplasty group was 6.21%±1.94%, that of the routine unipedicular PVP group was 5.22%±2.07% and that of the routine bipedicular PVP group was 5.97%±2.09%; there was 1 cement leakage case in the per-cutaneous curved vertebroplasty group; those of the routine unipedicular PVP group were 4 cases and those of the routine bipe-dicular PVP group were 6 cases; there was no significant difference among the three groups (P>0.05). Operation time 39.10±2.00 min vs 38.70±1.70 min, injected cement volume 3.60±0.11 ml vs 3.50±0.13 ml and blood loss 5.10±0.30 ml vs 5.00±0.40 ml of the percutaneous curved vertebroplasty group and the routine unipedicular PVP group were less than those of the routine bipedicular PVP group, which were statistically significant (P<0.05). Conclution Percutaneous curved vertebroplasty could achieve satisfactory clinical outcomes for OVCFs, with advantages of less operation time, less blood loss, limited X-ray expo-sure, less injected cement volume, and more balanced augmentation for stabilization of the affected vertebrae and total verte-bral column.

Objective To investigate high risk human papillomavirus(HR-HPV)prevalence among married women in Beijing and to study the high risk flactors.nethods During March 2007 to September 2008.a total of 6185 married women sampled from 137 communities in 12 districts were screened bv HR-HPV DNA test and cytogical test.The interview was carried out with unified questionnaires.The databage was set up and twice entered in EpiDam 3.0.After checked up,the data were analyzed in SPSS 15.0.Results (1) The HR-HPV infection rate was 9.89%.The HR-HPV infection rate of the city zone,the suburb and the exurb were 9.34%,10.51% and 9.51% (P>0.05).The HR-HPV infection rate of the native and the oudander were 9.53%,11.30% (P<0.05).(2) The age distribution of HR-HPV infection was that the rate was around 10% among 25 to 44 age groups,which was the highest(11.21%) in 30 to 34 age group;then the rate was descended as the age raising,the rate of 50 to 54 age group was the lowest(7.78%).(3) Multiple logistic regression showed that the related risk factors of HR-HPV infection mainly included 1000 RMB and above of family income per person per month.possessing more than 1 sexual partner of her husband,outlander and hish levels of education.(4) The prevalence of cervical intraepithelial neoplasia(CIN)in HR-HPV positive group wag significantly higher than that in HR-HPV negative group(29.76% vs 3.32%,P<0.01).Conclusions(1)The HR-HPV infection rate among aged 25 to 54 years was 9.9% and there was no significant difference in area distribution.(2)The hish risk population which should strengthen screening was the married bearing-age women with high level of family income,outlander,high levels of education and her husband possessing more than 1 sexual partner.(3)HR-HPV infection is the main risk factor for CIN and cervical cancer.while does not provide a causal relationship with them.The high risk population should be checked regularly to understand the development of HR-HPV infection and CIN incidence.

Alzheimer's disease （AD） is a chronic neurodegenerative disorder characterized by the progressive loss of cognitive and memory functions. Its pathological features mainly include neurofibrillary tangles formed by the aggregation of hyperphosphorylated tau proteins and amyloid plaques formed by the accumulation of β-amyloid. The exact pathogenesis of AD has not been fully elucidated， and there are currently no effective specific drugs or radical treatments available in clinical practice. In recent years， the incidence of AD has been on the rise， severely affecting life and health， making the search for effective drugs and therapeutic components for AD treatment crucial. Modern medical research has found that the brain-derived neurotrophic factor （BDNF）/tropomyosin receptor kinase B （TrkB） signaling pathway is closely related to neurogenesis， apoptosis， neuroinflammation， synaptic plasticity， and oxidative stress， playing a vital role in the pathophysiological development of AD. Additionally， Chinese medicine has a long history of treating neurodegenerative diseases with few adverse reactions and features a multi-target， multi-link， and multi-pathway approach to treatment. Therefore， the author reviewed the latest research reports in China and abroad to elaborate on the role of the BDNF/TrkB signaling pathway in the onset and progression of AD， and summarized the research progress on the regulation of the BDNF/TrkB pathway by Chinese medicine compounds and monomers in AD intervention. This study is expected to provide references for the development of clinical drugs for the prevention and treatment of AD and to broaden the perspective on Chinese medicine treatment of AD.